1. Field of the Invention
The present invention relates to a superconducting thin film, a superconducting device and a method for manufacturing thereof, and more specifically to a superconducting thin film formed of an oxide material, which has an oxide layer improving quality of the superconducting thin film, a superconducting device utilizing the superconducting thin film and a method for manufacturing thereof.
2. Description of Related Art
Fundamental devices which utilize superconductivity operate at a higher speed and/or lower power consumption so that they will have far better performance compared with those of semiconductor devices. The oxide superconductor materials which have been recently advanced in study make it possible to prepare superconducting devices which operate at relatively high temperature.
Superconducting devices have superconducting parts such as superconducting electrodes, superconducting channels, etc. These superconducting parts are usually formed of superconducting thin films. In order to prepare the superconducting parts, it is necessary to finely process superconducting thin films in order to obtain extremely fine structures. In this connection, it is desirable that the superconducting thin film has an ultra thin thickness.
An oxide superconductor has a layer-ed crystal structure and it is possible to stack in order each layer of the oxide superconductor crystal by an MBE (molecular beam epitaxy) process so as to form a crystalline oxide superconductor thin film. Therefore, it is also possible to form a crystalline oxide superconductor thin film in which crystalline lattices are disposed to constitute one unit-cell layer by an MBE process.
However, superconducting current does not flow in the crystalline oxide superconductor thin film of one unit-cell, therefore it is necessary to stack at least two unit-cells of crystalline lattices to form an oxide superconductor thin film in which superconducting current flows.